Protected 18650, meaning of "PCB is tripped" ?

I couldn’t say one way or another but from the written wording it does appear to be useless if tripped.
That’s not how a normal LVP battery circuit works. Never heard of one like this, unless they are talking about the factory CID or PTC.
They say it stops the battery from working and can not be reset. Even if a LVP circuit fails you can still unwrap the battery and take off the circuit board and use the battery unprotected. So it could still be used if they are talking about a circuit board.
If they are talking about the CID or PTC then its no different than any other factory battery that uses these features, which most do.
Its really not clear what protection it has. :person_facepalming:

Unprotected cells (≈65 mm lenght). Protected cells are always a few millimeters longer, usually between 68 to 70.5 mm.

That headlamp is unlikely to over-discharge the cells. If in doubt, stop being adamant and test it. See what I said above in #7. Leave the lamp powered on with cells inside for 2 - 3 days, the emitter will be barely lit after that time. I am pretty sure it uses some sort of unregulated and/or linear driver, current drain drops as battery voltage drops and collapses over the emitter Vf. You'll need a multimeter to check cell voltages. You can check cell voltage from time to time if you will.

well, lets assume there is no protection in the batteries and no protection in the light, for sake of example

now imagine you are using the light and it starts to get very very dim. Noticeably very very dim… I mean DIM!

well, thats a warning that the battery is reaching exhaustion.

the prudent thing to do, if you are going to use LiIon, is to have a way to test the battery voltage. Especially when the light gets DIM!

avoid draining the battery below 3.6 volts… but when the light gets dim, the battery may already be at 2.7 volts. The only way to use unprotected LiIon safely, is to measure the voltage periodically, even before the light gets Dim…

agree!

As jon-slider says the light is going to become very dim when the battery voltage is low.
You can look at TA’s xp-l2 test data and look at the vf (blue) vs Output (orange).

This is the actual voltage to the led. A battery will have voltage sag under a current load.
This is only a example, leds have different vf’’s at the same current but they are typically close.
At a loaded battery voltage of 2.5v your going to be almost in the dark. Once the load is removed the battery voltage will bounce back.
You should be able to recognize the battery is getting low visually way before the battery is at 2.5v loaded.
.
This does depend on what mode your are in though. If your using the light in low mode and only drawing a few ma’s then your probably not going to notice much change in output until the battery is below 2.5v loaded. Best to check voltages but using in a higher mode will let you know once you have done it a few times.

Thanks jon-slider and you too 007. Now this explains everything (bold emphasis added). I am much less concerned now because I am confident I will be able to detect visually when the light get uncomfortably dim. I don’t have an instrument to measure voltage and even if I have, I prefer not to bring it with me during a hike.

I didn’t know that a LED will stop functioning around 2.5V. I thought it uses the Li-ion cell like a gas tank. It stops when the tank is empty which to me is equivalent to 0V and means dead cell. With this gas tank analogy, a cell around 2.7V to 2.5V is more than 50% full. So I thought the LED should continue to work perfectly, even though it is about to kill the battery.

So then problem solved. Usually I finish the hike before the light gets noticeably dim. When it did, I switched to a backup light. Nevertheless, I will follow your advice to buy a multimeter. For the sake of learning to get acquainted with caring Li-ion cells.

Better yet, get a flashlight with Anduril UI. Three clicks gives an approximation of battery voltage… close enough for practical purposes. Check it with a cheap DMM (Harbor Freight under five bucks) if you want a correction. Carry an extra battery and change it at your desired discharge voltage, maybe 3.4 or 3.5V or whatever you wish. Your battery will last longer by avoiding deep discharge cycles that cause increased anode degradation.

Those two batteries you received with the headlamp are unprotected. It’s the same wrap used on protected and unprotected, Sofirn used the same wrap on the first version without protection until someone on BLF mentioned it. Their battery now has a black wrapper.

I’d just plain stay away from anything that cheap. Usually a safety risk

Any of you grabbed some led MCPCB and did the diode test with a multimeter? Diode test current is quite a low value (<2 mA), and you should see a value of ≈2.45 V on the multimeter's screen at that current. When you add a tiny driver plus other parts voltage drop overhead, you know cell voltage is quite unlikely to drop below 2.5 V even if left unattended for a while, and definitively will never drop below 2 V which is the absolute minimum value for li-ion cells safety wise. I tested what I say here attaching a couple of old cells to an led with some thin wires and magnets, and waiting until the die would very barely glow.

I won't repeat myself with this @#$%. And don't be anal with the too low voltage on a cell (as some of you take it), it's a bs thing in my opinion. I do not mean to say it may not matter, but ask yourself how much actual time will a cell remain at 2.5 - 3 V in a flashlight, probably very little if at all.

Sun, 03/15/2020 - 04:38

Anduril isn’t everyone’s cup of tea, way too many options and config being only 4 clicks, is annoying for some. It’s way too close to everything else. NarsilM was 16s hold and couldn’t be accessed by accident

I enjoy Anduril myself but would prefer config to be changed

The only thing that is a exception to this (light output is getting dim my battery voltage is low) is a light that excepts alkalines, Nimh and li-ion.
They contain a boost driver for Alkaline or Nimh. Once the battery falls below the vf of the led at a current load, the boost circuit kicks in and tries to maintain the current to the led. Most of these type drivers dont have any kind low voltage warning for li-ion. They can’t distinguish between if your using a Nimh or a very low voltage li-ion.

Barkuti is my battery management guru, but on this one point I disagree based upon a study. It has more data than I care to assimilate, but some of it is worth reading.
From another thread:
docware wrote: The study is dated 19.4.2017, cells are Panasonic NCR18650PD. You can read the whole study here :

It reads:
Rdc,10s (related to the charge transfer resistance of the NCA cathode) has increased by ca. 60% when discharging to 3.4 V, whereas it has increased by more than 200% when discharging to 2.5 V (from 4.1v. at 25C). Hence, microcracks of the NCA cathode and weakened particle contacts are assumed to aggravate with larger cycle depths and cause the marked impedance increase.

While I agree with anyone that says terminating a charge early or not draining a cell to low will prolong life of a cell.
My thoughts are that I usually only cycle any one particular battery of mine a few dozen times a year. I just have several batteries with several different lights.
So any one battery doesn’t get used that much per year. Then about every two years or so out comes a better battery in the same format. Like most people I buy a few to replace my out dated cells. I never really use any cells longer than about 4 years with a few hundred cycles on them, I have newer better cells to use.
So while draining them to 2.5v that’s suggested lowest in most data sheets could be considered abusing them. I will probably never see the day when it actual matters becuse I have already replaced them with something better.
Not everone will feel this way, and some people will want the cells to last as long as possible which is fine. Nothing wrong at all having health cell practices.
.
I have mixed feelings about what I read in datasheets and some test data. When you use cells outside what the test data showed or outside what’s in the datasheets things change a little, kind of uncharted territory in the cell data world. There were a few peolpe that experienced this uncharted territory in this thread.

That’s a interesting thread on battery voltage being to low.
Most of us received batteries that had been setting on a shelf for 3 years never used and measured 1.9v upon arrival. As comfychair said ” they appeared to be just taking a little nap”. I still have those cells at 11 years old now. Its about due for another discharge test.
.
If I was using them hiking and needed the light to see, it definetly wouldn’t bother me to squeeze ever last lumen out of the cell.

adjust your assumption:
the gas tank is empty at 2.7v
it is half empty at 3.6v

read
Lithium Ion Battery Safety 101

test
use your light until you notice it get dim, confirm the battery voltage on a meter at that point

now a warning
using a light with Two Batteries has a additional risk, IF they are not of matched charge. It is possible for the battery with higher charge, to transfer power into the less charged battery. This is dangerous. Therefore, I would not recommend a light with two batteries, to a newbie, unless they are of equal charge, age, condition. Dont mix and match batteries with different charge levels.

battery chemistry
Unprotected ICR is most dangerous
Unprotected IMR and INR is less dangerous

Read
https://batterybro.com/blogs/18650-wholesale-battery-reviews/18880255-battery-chemistry-finally-explained

On another note, I’ve had two cells (18650, 26650) that appear to have protection circuits in them.
The cells were 70mm long with button tops and space for the protection.
Both had the higher resistance expected from protected cells.
One was an 18650 crap cell included with an “as seen on TV” zoomie that tested way below the rated “5000mAh” (naturally).
The second was a 26650 that was rated at 5000mAa and tested to 5400mAh – a nice surprise.
This was included with an $11 light from Amazon.

In both cases the lights and the cell protection allowed the cells to be discharged below 2.5v.
So it would seem that there are some “protected cells” that the protection may not do what we normally expect.

I wonder just what would trigger the protection? It’s not undervoltage.
Perhaps an over current situation is what these are designed for?

This maybe what you have going on with your setup.
All the Best,
Jeff

Protection doesn’t always work so never rely on it. Learn about lithium safety and use with a flashlight that is confirmed to have a low voltage cut off.

Jeff51 - sometimes cheap protection chips cut off lower than 2.4v so you may have not taken it low enough yet.

I’ve had cheap cells with protection charge when reversed in a charger. Scary stuff. Gave an error inserting the correct way but started charging when reversed

I had 2 incidents with battery tripping.

My Sofirn 14500 tripped so I zapped it with 12v just briefly. It worked in flashlight, stored it away and then no work few weeks later in flashlight.

My Pansonic Eneloop Pro AA went to 0V. It wouldn’t charge again right away. Few hours later put back in charger and it started to charge. Now it’s fully charged and okay! :smiley:

Hope this helps. :slight_smile:

A protection pcb is a electronic circuit with electronic components. It is a electronic form of protection for the battery running outside of acceptable perimeters.
A TV is a electronic circuit with electronic components, you ever had one fail?
Its there just incase the user doesn’t follow proper use. They do fail and sometimes dont trip at the right times.
Its better to learn proper use, and use the protection circuit as a back up.
Its like driving and using the seatbelt to save you from your bad driving all the time. Learn to drive properly and you want need to rely on the seatbelt. :smiley:

I’ve had no trouble reviving protected cells with low voltage protection tripped.
Some chargers will do it just fine. I’ve also had cheap headlamps with built-in charging do it also.
This is with no-name protected cells that came with the headlamps.
These lights have no built in protection. They run till you think it gets too dim or until the LVP tripps.
I’ve done this several times with these lights.

Also you can just use a working cell to reset the protection.
All that’s needed is to put the “tripped” cell in parallel with the working cell.
It would be a good idea to use a resistor in between to prevent a big current surge.

Others have used a pair of AAA in series to provide 3v to put in parallel with the tripped cell.

I have seen POSTs where the protection circuit has died and no tricks work to bring it back.
In that case the cell might be just fine.
Remove the wrapper and disconnect the electronics, check the voltage, and presto – a working non-protected cell.
A little more info from HKJ
https://lygte-info.dk/info/battery%20protection%20UK.html
All the Best,
Jeff

Thanks for the reference links. I had read those before but somehow I failed to notice that a LED will stop working properly when the cell is close or reaching the cutoff low voltage. Now that I know this detail. I will just go will unprotected Samsung INR18650-35E. I have no usage of high current, careful by nature and I use a Nitecore new i2 charger. I think that I could manage with unprotected cells. The overhead of the protection mechanism may even be counter-productive for my case.

Once I receive the new cells, I will proceed for the test procedure you advised to learn about the safe runtime of the cell. This headlamp uses 2x 18650 in parallel. When I remove one, it works perfectly with the same brightness. So I think I will carry the 2nd as backup cell to avoid the multi-cells scenario.

I have the exact same headlamp and it drains the cells below 2v.

This hasn’t been my experience. I’ve had many flashlights with no low voltage protection discharge under 2v

2.5v on load should be the absolute minimum but not all batteries, you need to check the datasheet for each model. The reviewer HJK has stated that he no longer runs tests down to 2.5v anymore due to ruining some batteries, he now only tests to 2.8v.

I do however just immediately switch off a light once it goes dim. If you leave it on once it’s dim it’ll very quickly drop too low.

Do not attempt to charge a battery that’s under 2v unless you know what you’re doing.

Did you get that? safety wise, not ruling out damaging your batteries irreversibly.